Bearing Assembly for a Disk Gang

Abstract

A bearing assembly ( 20 ) with a self-lubricated liner interface ( 70 ) supported between a spherical outside surface ( 72 ) of a sealed agricultural bearing ( 20 b ) and a steel containment housing ( 60,62 ). The interface ( 70 ) includes a lubrication-impregnated plastic interposed between the housing ( 60,62 ) and the spherical surface ( 72 ) to relieve the bearing from the high forces of shaft misalignment. The plastic liner includes a compressible portion such as radially projecting protrusions ( 82 ), O-rings ( 82 a ) or other resilient band, or compressible molded plastic (H 2 ) to accommodate varying tolerances between the outside spherical surface ( 72 ) and housing cavity surfaces ( 68 ) and liner ( 70 ) and to bias the liner ( 70 ) against the spherical surface ( 72 ) to prevent bearing rotation. The plastic liner halves ( 70 a, 70 b ) fit firmly over the outside bearing surface to reduce entry of dirt and contaminants into the housing and onto the spherical bearing surface ( 74 ). The sealed bearing ( 20 b ) and self-lubricated interface ( 70 ) eliminate need for external grease ports.

1 . In a self-aligning bearing assembly for supporting an implement shaft for rotation about a shaft axis in a harsh operating environment, the shaft axis moveable a limited amount from a first aligned position, the assembly including a bearing with an outer race and an outer spherical surface, a bearing inner race supported within the outer race for rotation about an inner race axis, and a containment housing with housing surfaces defining a containment cavity supporting the outer spherical surface and facilitating movement of the inner race for self-alignment of the inner race axis with the shaft axis as the shaft axis moves from the first aligned position, connecting structure for securing the bearing within the containment housing, the improvement comprising;
 a compressible bearing liner having opposed liner surfaces interposed between the outer spherical surface and the housing surfaces of the containment cavity, wherein the bearing liner comprises an inner spherical surface conforming to a portion of the outer spherical surface and an outer portion conforming generally to the containment cavity, the bearing liner compressed between the containment cavity and the outer spherical surface of the bearing for non-rotatably securing of the bearing within the housing and taking up tolerances between the outer spherical surface of the bearing and the containment cavity of the containment housing.   
     
     
         2 . The bearing assembly as set forth in  claim 1  wherein the bearing liner comprises a lubricant-impregnated plastic liner having in inner spherical friction-reducing liner surface for reducing wear between the liner and the outer spherical surface during the self-alignment, the inner spherical liner surface and the outer spherical surface of the bearing having radii approximately equal to each other. 
     
     
         3 . The bearing assembly as set forth in  claim 1  wherein the bearing liner includes a compressible liner portion projecting from the outer portion of the liner for accommodating tolerance between the containment cavity of the containment housing and the outer spherical surface of the bearing and providing a tight grip of the inner spherical surface of the liner on the outer race. 
     
     
         4 . The bearing assembly as set forth in  claim 3  wherein the compressible liner portion includes on O-ring supported by the plastic liner. 
     
     
         5 . The bearing assembly as set forth in  claim 3  wherein the compressible liner portion comprises protrusions molded into the liner. 
     
     
         6 . The bearing assembly as set forth in  claim 3  wherein compressible liner portion comprises first and second liner halves assembled over the spherical bearing, the liner halves including compressible projections and anti-rotation tabs projecting radially from the halves, wherein the containment housing includes mating recesses receiving the anti-rotation tabs. 
     
     
         7 . The bearing assembly as set forth in  claim 3  wherein the bearing liner comprises a plastic material molded directly into the containment cavity of the containment housing. 
     
     
         8 . The bearing assembly as set forth in  claim 1  wherein the liner comprises an inner self-lubricating outer race support and a compressible liner portion bearing against the housing surfaces and urging the liner against the outer race. 
     
     
         9 . The bearing assembly as set forth in  claim 8  wherein the self-lubricating outer race support comprises a first high strength self-lubricating plastic material and the compressible liner portion comprises a second plastic material of durometer less than the first plastic material. 
     
     
         10 . The bearing assembly as set forth in  claim 8  wherein the compressible liner portion includes plastic compressible projections extending radially outwardly from the outer portion of the liner to bias the outer race support into engagement with the outer race. 
     
     
         11 . The bearing assembly as set forth in  claim 1  wherein the improvement further comprises:
 the liner fabricated from a self-lubricating plastic material; 
 the bearing comprising a sealed pre-lubricated bearing; and 
 wherein the bearing assembly is void of external grease ports. 
 
     
     
         12 . In a self-aligning bearing assembly for supporting an implement shaft for rotation about a shaft axis in a harsh operating environment, the shaft axis moveable a limited amount from a first aligned position, the assembly including a bearing with an outer race and an outer spherical surface, a bearing inner race supported within the outer race for rotation about an inner race axis, and a containment housing defining a containment cavity supporting the outer spherical surface and facilitating movement of the inner race for self-alignment of the inner race axis with the shaft axis as the shaft axis moves from the first aligned position, structure for securing the bearing within the containment housing, the improvement comprising;
 a bearing liner fabricated from a self-lubricating plastic material compressed between the containment cavity and the outer race;   the bearing comprising a sealed pre-lubricated bearing; and   wherein the bearing assembly is void of external grease ports.   
     
     
         13 . The bearing assembly as set forth in  claim 12  wherein the plastic material is molded with an outer surface conforming generally to the containment cavity and an inner spherical surface conforming to a portion of the outer spherical surface. 
     
     
         14 . The bearing assembly as set forth in  claim 12  wherein the bearing liner includes a compressible liner portion projecting from the liner for accommodating tolerance between the containment cavity of the containment housing and the outer spherical surface of the bearing and providing a tight grip of the inner spherical surface of the liner on the outer race. 
     
     
         15 . The bearing assembly as set forth in  claim 14  wherein the compressible liner portion includes a resilient band member. 
     
     
         16 . The bearing assembly as set forth in  claim 14  wherein the compressible liner portion comprises protrusions molded into the liner. 
     
     
         17 . The bearing assembly as set forth in  claim 14  wherein compressible liner portion comprises first and second molded liner halves assembled over the bearing, the liner halves including compressible projections and locating tabs projecting radially from the halves, wherein the containment housing includes mating recesses receiving the locating tabs. 
     
     
         18 . The bearing assembly as set forth in  claim 12  wherein the bearing liner comprises a plastic material molded directly into the containment cavity of the containment housing. 
     
     
         19 . The bearing assembly as set forth in  claim 12  wherein the bearing liner comprises an inner self-lubricating outer race support and a compressible liner portion bearing against the housing surfaces and urging the liner against the outer race. 
     
     
         20 . The bearing assembly as set forth in  claim 19  wherein the self-lubricating outer race support comprises a high strength self-lubricating first plastic material and the compressible liner portion comprises a second plastic material of durometer less than the first plastic material.